In a wide variety of circumstances, animals, including humans, can suffer from bleeding due to wounds or during surgical procedures. In some circumstances, the bleeding is relatively minor, and normal blood clotting functions in addition to the application of simple first aid are all that is required. In other circumstances substantial bleeding can occur. These situations usually require specialized equipment and materials as well as personnel trained to administer appropriate aid.
In an effort to address the above-described problems, materials have been developed for controlling excessive bleeding. Topical Absorbable Hemostats (TAHs) are widely used in surgical applications. TAHs encompass products based on oxidized cellulose (OC), oxidized regenerated cellulose (ORC), gelatin, collagen, chitin, chitosan, etc. To improve the hemostatic performance, scaffolds based on the above materials can be combined with biologically-derived clotting factors, such as thrombin and fibrinogen.
The control of bleeding is essential and critical in surgical procedures to minimize blood loss, to reduce post-surgical complications, and to shorten the duration of the surgery in the operating room. Due to its biodegradability and its bactericidal and hemostatic properties, oxidized cellulose, as well as oxidized regenerated cellulose has long been used as a topical hemostatic wound dressing in a variety of surgical procedures, including neurosurgery, abdominal surgery, cardiovascular surgery, thoracic surgery, head and neck surgery, pelvic surgery and skin and subcutaneous tissue procedures. A number of methods for forming various types of hemostats based on oxidized cellulose materials are known, whether made in powder, woven, non-woven, knit, and other forms. Currently utilized hemostatic wound dressings include knitted or non-woven fabrics comprising oxidized regenerated cellulose (ORC), which is oxidized cellulose with increased homogeneity of the cellulose fiber. Examples of such hemostatic wound dressings commercially available include SURGICEL SNoW® Absorbable Hemostat; SURGICEL® Original Absorbable Hemostat; SURGICEL® FIBRILLAR™ Absorbable Hemostat; SURGICEL NU-KNIT® Absorbable Hemostat; all available from Johnson & Johnson Wound Management Worldwide, a division of Ethicon, Inc., Somerville, N.J., a Johnson & Johnson Company. Other examples of commercial resorbable hemostats containing oxidized cellulose include GelitaCel™ resorbable cellulose surgical dressing from Gelita Medical BV, Amsterdam, The Netherlands. The commercially available oxidized cellulose hemostats noted above are knitted or nonwoven fabrics having a porous structure for providing hemostasis.
Hemostatic materials can also be provided in powdered form, such as for example powders based on purified plant starch, clay, zeolite granules, fibrinogen, thrombin, mixtures of fibrinogen and thrombin, etc. There is a need in delivering these and similar hemostatic materials in a powder form to the surface of tissue or wound for controlling bleeding.
The existing devices for delivering hemostatic powders lack uniformity in delivery, with quantity of powder delivered at the beginning of expression varying from quantity of powder delivered at the end of the expression. Also the existing device have significant variability in powder delivery under varying angles of spray, i.e. when orientation is changing from horizontal to vertical and any angle in-between. Further, the existing devices might not perform well in laparoscopic delivery modes, may clog, or may express some powder prior to actuation, i.e. due to powder leakage from the devices.
U.S. Pat. No. 6,866,039 discloses a dispensing apparatus for dispensing a powdered product comprising: a housing defining an outlet, a shaft having a storage chamber therein for a powdered product provided with a first inlet and a first outlet, a sheathing member slidably mounted on the shaft and having a second inlet and a second outlet closed by a frangible membrane, and a variable volume member operatively connected to the shaft; wherein the shaft is moveable, on operation of the variable volume member to reduce the variable volume so as to pressurize gas in an interior of the variable volume member, from an initial storage position in which the first and second inlets are out of alignment so as to close a gas flow path, to a dispensing position, in which the first and second inlets are brought into alignment by action of the housing against the sheathing member and in which the frangible membrane is ruptured by the shaft so as to open the gas flow path, such that pressurized gas from the interior of the variable volume member is discharged along the gas flow path comprising the first and second inlets, storage chamber, second outlet and first outlet, to thereby entrain powdered product and dispense it through the housing outlet.
U.S. Pat. No. 8,056,762 discloses a hand-held dispenser for dispensing a pharmaceutical product, the dispenser comprising: a housing providing a duct; a frangible membrane provided in the duct; a probe with a piercing tip mounted in the duct, the probe being arranged such that, in use, the piercing tip pierces the frangible membrane; an air compression device to compress air for expelling a pharmaceutical product through the probe; and a channel to substantially equalize the pressure in the air compression device and the pressure above the frangible membrane, wherein the frangible membrane is provided on a sheath which comprises a first larger diameter portion and a second axially spaced smaller diameter portion defining an external shoulder therebetween, and the inside surface of the duct has a corresponding internal shoulder to be engaged by the external shoulder of the sheath and an axial spacer is provided on one or both of the external and internal shoulders to maintain the channel past the engaged shoulders.
Published U.S. Patent Application 2012/0103332 discloses a powder delivery device, comprising: a body; a nasal adapter; a piercing device between the nasal adapter and the body; a blister between the piercing device and the body, wherein the blister contains a powder; a bellows; a spring; and an actuator.
U.S. Pat. No. 7,923,031 discloses a powder delivery system comprising: a chamber storing a hemostatic composition comprising dry gelatin powder having a mean particle size in the range of 30-250 micrometers and hyaluronic acid, said chamber having at least one discharge opening sized for distributing said composition.
European Publication No. 1,322,356 discloses a device for delivering multiple doses of physiologically active agent in powdered form, the device comprising: a manually rechargeable air reservoir; a powder container defining therein a plurality of individual receptacles, each receptacle containing a discrete metered dose of powder, a powder delivery passage for the forced flow therethrough to a patient of air with a said metered dose of powder entrained therein so as substantially to empty a said receptacle, a closure for restricting the unwanted ingress of moisture into the device via said passage when the device is not in use; and a container indexing mechanism for indexing movement of said container to move a substantially empty said receptacle out of communication with said powder delivery passage and to move a fresh powder-containing said receptacle into communication with said powder delivery passage; wherein the device is constructed and arranged so that the action of opening or closing said closure (i) operates said container indexing mechanism and (ii) charges the air reservoir with air.
European Publication No. 2,042,208 discloses a dispensing device for dispensing a formulation as a spray, wherein the dispensing device is adapted to receive or comprises a storage device with at least one or multiple, preferably separate and pre-metered doses of the formulation, wherein the dispensing device comprises a means for pressurizing gas, in particular air, or an air inlet for generating or allowing a gas stream flowing through the storage device for dispensing a dose of the formulation, characterized in that the dispensing device is designed such that pressure pulses are generated in the gas stream during dispensing one dose and/or the direction of gas flow alternates during dispensing one dose.
U.S. Pat. No. 7,540,282 discloses an inhaler, comprising: a sealed reservoir including a dispensing port; a linear channel communicating with the dispensing port and including a pressure relief port; a conduit providing fluid communication between an interior of the sealed reservoir and the pressure relief port of the channel; a cup assembly movably received in the channel and including, a recess adapted to receive medicament from the reservoir when aligned with the dispensing port, a first sealing surface adapted to seal the dispensing port when the recess is not aligned with the dispensing port, and a second sealing surface adapted to seal the pressure relief port when the recess is aligned with the dispensing port and to unseal the pressure relief port when the recess is not aligned with the dispensing port.
Chinese Patent publication No. 203263962 discloses a utility model that relates to a hemostatic dry powder spraying bottle. The hemostatic dry powder spraying bottle comprises a bottle body made of medical plastic, an inner spraying pipe made of medical plastic, an outer sleeve cap and a handle made of medical plastic, wherein a groove which allows the bottle body to stretch in the axial direction of the bottle body is formed in the outer surface of the bottle body, the inner spraying pipe is arranged on the top of the bottle body in a screwed mode through threads, the inner spraying pipe is sleeved with the outer sleeve cap, the lower end of the outer sleeve cap is connected with the bottle body, and the handle is fixedly connected with the bottle body. The hemostatic dry powder spraying bottle is simple and novel in structure, low in cost, convenient to use, even in exerted force, complete in powder spraying and good in powder spraying effect and hemostatic effect.
There is a need in improved delivery devices for delivering hemostatic powders to the surface of tissue or wound for controlling bleeding.